3,3′-Dinitroamino-4,4′-azoxyfurazan and Its Derivatives: An Assembly of Diverse N–O Building Blocks for High-Performance Energetic Materials

On
the basis of a design strategy that results in the assembly
of diverse N–O building blocks leading to energetic materials,
3,3′-dinitroamino-4,4′-azoxyfurazan and its nitrogen-rich
salts were obtained and fully characterized via spectral and elemental
analyses. Oxone (potassium peroxomonosulfate) is an efficient oxidizing
agent for introducing the azoxy N-oxide functionality
into the furazan backbone, giving a straightforward and low-cost synthetic
route. On the basis of heats of formation calculated with Gaussian
03 and combined with experimentally determined densities, energetic
properties (detonation velocity, pressure and specific impulse) were
obtained using the EXPLO v6.01 program. These new molecules exhibit
high density, moderate to good thermal stability, acceptable impact
and friction sensitivities, and excellent detonation properties, which
suggest potential applications as energetic materials. Interestingly,
3,3′-dinitroamino-4,4′-azoxyfurazan (4)
has the highest calculated crystal density of 2.02 g cm–3 at 173 K (gas pycnometer measured density is 1.96 g cm–3 at 298 K) for N-oxide energetic compounds yet reported.
Another promising compound is the hydroxylammonium salt (6), which has four different kinds of N–O moieties and a detonation
performance superior to those of 1,3,5,7-tetranitrotetraazacyclooctane
(HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclododecane
(CL-20). Furthermore, computational results, viz., NBO charges and
ESP, also support the superior qualities of the newly prepared compounds
and the design strategy.